Lapatinib is an active pharmaceutical ingredient used for the treatment of advanced metastatic lung cancer and is currently on the market under the name TYKERB™ (Lapatinib ditosylate monohydrate), sold by GlaxoSmithKline (GSK).
According to the manufacturer's instructions, the commercial product Tykerb contains Lapatinib as the ditosylate monohydrate salt of formula (I-bis):

having the chemical name N-{3-Chloro-4-[(3-fluorobenzyl)oxy]phenyl}-6-[5-({[2-(methylsulphonyl)ethyl]amino}methyl)furan-2-yl]quinazolin-4-amine bis(4-methylbenzenesulphonate) monohydrate, CAS RN 388082-78-8 and m.p. 250-256° C.
This substance can be prepared according to teachings of the prior art such as for example those contained in U.S. Pat. No. 7,157,466. In particular, in said reference, examples 10 and 11 show the preparation of the ditosylate monohydrate salt starting from the anhydrous ditosylate salt.
The aforementioned process suffers from the main disadvantage consisting in that said intermediates such as for example that having the aldehyde function in free form being poorly soluble, thus leading to low productivity. In other processes of the known art, stannane intermediates are used resulting in problems related to waste disposal. In general the known processes for the preparation of Lapatinb suffer of a low overall molar yield.